1. Field of the Invention
The present invention relates to a flat vibration motor built into a mobile phone etc., more particularly relates to a structure of a stator plate for the same.
2. Description of the Related Art
In the past, as a flat vibration motor, for example a brushless motor has been provided with a stainless steel disk shaped stator plate on which one end of a shaft is press fit into a burring part, a stainless steel U-sectional cover with an open part covered by the stator plate and to which the other end of the shaft is fit in a shaft mounting hole, a rotor plate having an axial direction field type rotor magnet and eccentric weight supported to be able to rotate via a slide bearing through which the shaft runs, and a flexible printed circuit board superposed on the stator plate and mounting a plurality of stator coils, current control IC's, and other electronic devices. The stator plate has a plurality of detent torque generating holes for avoiding cessation of rotation at the dead points of the rotor plate around the burring part.
Here, the stator plate, for convenience in feeding power to the required interconnect of the flexible printed circuit board, has an ear-shaped power feed terminal mount sticking out from the arc-shaped outer periphery outward in the radial direction. This is electrically connected to a power feed pattern on the device side board mounting this flat vibration motor through this flexible printed circuit board on this power feed terminal mount. Further, the stator plate is provided at a plurality of locations with detent torque generating holes. Due to this, there is the problem of entry of solder into these holes, so the plate has mounting legs sticking out from the arc-shaped outer periphery outward in the radial direction and can be fastened to the device side board mounting the flat vibration motor by reflow solder.
As related art, there is Japanese Patent Publication (A) No. 2005-27484 (FIG. 2).
In the above flat vibration motor, the stator plate has a power feed terminal mount and a plurality of mounting legs sticking out from the arc-shaped outer periphery outward in the radial direction, so these end up sticking out from the occupied area of the cover having the arc-shaped opening and additionally uses up space of the device side board mounting the flat vibration motor.
Further, the electrical connection to the device side board by the flexible printed circuit board and the mechanical fastening by the mounting legs are separate matters. The mounting work therefore becomes troublesome.